1. Field of the Invention
The present invention relates to a recording and/or reproducing apparatus, such as a VCR (video cassette recorder), which includes a tape loading mechanism which draws tape from a tape cassette and forms a tape path.
2. Description of Related Art
In a general VCR which is one example of a recording and/or reproducing apparatus, after a tape cassette has been mounted, magnetic tape is drawn from the tape cassette by tape guide members and is wrapped around a rotary cylinder.
FIGS. 1 and 2 show the manner in which magnetic tape 201 is drawn from a tape cassette 200 by tape guide members 4. As shown in FIG. 1, if the tape cassette 200 is mounted, the tape guide members 4 are positioned in an opening portion 200a of the tape cassette 200.
Then, in a tape loading operation, the respective tape guide members 4 are guided along slots 8 formed in guide members 3, and tape drawing posts 5 and 6 of each of the tape guide members 4 draw the magnetic tape 201 from the tape cassette 200. Then, as shown in FIG. 2, when the respective tape guide members 4 reach the terminal ends of the slots 8, the magnetic tape 201 is wrapped around a rotary cylinder 101 so that a predetermined tape path is formed.
Each of the tape guide members 4 which travel along the respective slots 8 in the tape loading operation in the above-described manner has the construction and arrangement shown in FIG. 3 by way of example.
FIG. 3 is a diagrammatic cross-sectional view showing one of the tape guide members 4 and the corresponding one of the slots 8 formed between guide member portions 3a and 3b as viewed in a direction perpendicular to the slot 8. The tape drawing posts 5 and 6 are disposed on the top of the tape guide member 4, and an engagement pin 10 is secured to the bottom of the tape guide member 4. This engagement pin 10 is guided by the guide member portions 3a and 3b so that the tape guide member 4 can travel along the slot 8.
A flange portion 9 which is enlarged in width is formed at the bottom end of the engagement pin 10. This flange portion 9 prevents the tape guide member 4 from coming off the slot 8 in the upward direction. To this end, the flange portion 9 is formed to have a width W' larger than a width W of the slot 8.
Projections 4a are formed on the bottom of the tape guide member 4. While the tape guide member 4 is traveling, the projections 4a slide in contact with the corresponding guide member portions 3a and 3b.
To reduce resistance to the projections 4a which are sliding on the corresponding guide member portions 3a and 3b, a distance t' from a top end face 9c of the flange portion 9 to the projections 4a is set larger than a thickness t of the guide member 3. A clearance s between the top end face 9c of the flange portion 9 and the guide member portions 3a and 3b is set equal on the opposite sides of the slot 8.
In the field of such recording and/or reproducing apparatus such as a VCR, it has recently been desired to make the entire size of the apparatus smaller and smaller for more improved portability. In such a situation, it has been necessary to provide an arrangement which enables the tape guide member 4 to travel not only in the horizontal direction but also in the vertical direction.
FIG. 4 is a diagrammatic cross-sectional view showing the tape guide member 4 which is arranged to travel in the direction of an arrow A over the guide member 3 having a shape which extends in the horizontal direction up to an intermediate portion and bends downwardly at the intermediate portion. If the guide member 3 has a bent portion 11 which bends in the vertical direction in the manner shown in FIG. 4, the thickness t of each of the guide member portions 3a and 3b substantially increases at the bent portion 11. To allow the tape guide member 4 to easily pass through the bent portion 11, it is necessary to set a distance t" from the top end face 9c of the flange portion 9 to the projections 4a to a value greater than the distance t' shown in FIG. 3.
However, if the distance t" from the top end face 9c of the flange portion 9 to the projections 4a is set greater to allow the tape guide member 4 to easily pass through the bent portion 11, there is the disadvantage that the play between the tape guide member 4 and the guide member portions 3a and 3b increases in portions other than the bent portion 11.
In addition, there has been a risk that, owing to this play, the tape guide member 4 and the tape drawing posts 5 and 6 incline more than necessary and scratch the tape. There has also been a risk that if such inclination occurs while the tape guide member 4 is passing the vicinity of the rotary cylinder 101, the tape drawing posts 5 and 6 come into contact with and scratch the rotary cylinder 101.
The aforesaid arrangement which makes it possible to reduce the entire size of the apparatus, i.e., the arrangement which enables the tape guide member 4 to travel not only in the horizontal direction but also in the vertical direction, also has a number of problems connected with a positioning member for the tape guide member 4, as will be described below.
FIGS. 5(a) and 5(b) show different examples of an abutment portion for the positioning member. The end faces of the abutment portion for the tape guide member 4 are formed by faces approximately perpendicular to a surface (for example, the top surface as viewed in FIG. 5(a)) of a main chassis 102, as shown in FIG. 5(a), or by faces approximately perpendicular to a surface (for example, the top surface as viewed in FIG. 5(b)) of the positioning member 2, as shown in FIG. 5(b).
However, if the positioning member 2 has the construction shown in FIG. 5(a), moment occurs due to couples such as those shown by arrows A in FIG. 5(a) in a positioning pin 21 which is brought into abutment with an abutment portion 2a (refer to FIG. 1) having an approximately V-shaped notch. This moment works in the direction opposite to the direction of moment which originally works on the tape guide member 4 for positioning the tape guide member 4 at a predetermined position. Therefore, such moment has the problem of remarkably impairing the positioning stability of the tape guide member 4.
In these days, in many cases, to reduce manufacturing costs, positioning members have been formed by molding (with a plastic material) integrally with a rotary drum base. However, to constitute the positioning member 2 as shown in FIG. 5(b), in its manufacturing process, it is necessary to provide a mold with a predetermined slide mechanism for the purpose of removing the positioning member 2 from the mold, so that a mold having an extremely complicated structure is needed and the manufacturing costs increase. Further, in this case, since a multiplicity of products (the positioning member 2) are difficult to handle at a time, there is the problem that molding costs increase.